Trees Made Stronger by Bending in the Wind

A number of years ago, researchers in Illinois (as I recall) placed a number of young trees in a greenhouse. One group was supported by (tied to) a stake. A second group was left to grow unstaked. And a third group was left unstaked but manually waved back and forth for several minutes every day. At the end of several months, the three groups of trees were measured for growth in height and trunk diameter. The staked trees were the tallest and weakest (small trunk diameter), the unstaked trees were intermediate in height and trunk diameter, and many were not growing straight. The unstaked trees that were waved back and forth each day were the shortest but had the greatest trunk diameter, thus were the strongest.

This research showed that when you plant a tree, it should only have enough support to allow it to stand upright. Let the top of the tree wave in the wind to promote the development of a strong trunk.